This research discovered that shiitake mushrooms produce oxalic acid, which can effectively kill harmful bacteria that cause plant diseases. The study found that the waste material left after growing shiitake mushrooms contains high levels of this beneficial compound, suggesting a sustainable way to use mushroom byproducts for protecting crops. Impacts on everyday life: • Provides a natural alternative to chemical pesticides for farmers and gardeners • Offers a way to recycle mushroom growing waste into useful products • Could lead to more sustainable and environmentally friendly farming practices • May reduce food waste by protecting crops from bacterial diseases • Demonstrates the additional benefits of mushroom cultivation beyond food production